package com.webserver.http;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.net.Socket;

/**
 * 响应对象
 * 该类的每一个实例用于表示服务端给客户端发送的一个HTTP响应内容。每个响应由三部分构成:
 * 状态行，响应头，响应正文
 */
public class HttpResponse {
    //状态行相关信息
    private int statusCode = 200;//默认值200
    private String statusReason = "OK";//默认值OK

    //响应头相关信息


    //响应正文相关信息
    private File entity;//响应正文对应的实体文件

    private Socket socket;
    public HttpResponse(Socket socket){
        this.socket = socket;
    }

    /**
     * 将当前响应对象内容以标准的响应格式发送给客户端
     */
    public void flush() throws IOException {
        //1发送状态行
        sendStatusLine();
        //2发送响应头
        sendHeaders();
        //3发送响应正文
        sendContent();
    }

    private void sendStatusLine() throws IOException {
        String line = "HTTP/1.1"+" "+statusCode+" "+statusReason;
        println(line);
    }
    private void sendHeaders() throws IOException {
        String line = "Content-Type: text/html";
        println(line);

        line = "Content-Length: "+entity.length();
        println(line);

        //单独发送CRLF表示响应头发送完毕
        println("");
    }
    private void sendContent() throws IOException {
        try(
            //利用异常处理机制的自动关闭特性，确保文件流使用后被关闭
            FileInputStream fis = new FileInputStream(entity);
        ) {
            OutputStream out = socket.getOutputStream();
            byte[] data = new byte[1024 * 10];//10kb
            int len;//每次实际读取到的字节数量
            while ((len = fis.read(data)) != -1) {
                out.write(data, 0, len);
            }
        }//这里不写catch是因为异常抛出给流程控制来处理。
    }
    private void println(String line) throws IOException {
        OutputStream out = socket.getOutputStream();
        byte[] data = line.getBytes("ISO8859-1");
        out.write(data);
        out.write(13);//发送一个回车符
        out.write(10);//发送一个换行符
    }

    public int getStatusCode() {
        return statusCode;
    }

    public void setStatusCode(int statusCode) {
        this.statusCode = statusCode;
    }

    public String getStatusReason() {
        return statusReason;
    }

    public void setStatusReason(String statusReason) {
        this.statusReason = statusReason;
    }

    public File getEntity() {
        return entity;
    }

    public void setEntity(File entity) {
        this.entity = entity;
    }
}






